Carburetor for high-pressure valves



June 12, 1951 J. B. ROGERS 2,556,822

7 CARBURETOR FOR HIGH-PRESSURE VALVES Filed May 10, 1948 zit/1T IPatented June 12, 1951 UNITED CARBURETOB; FOR HIGH-PRES SURE VALVES JohnBerrien Rogers,.Pasadena, Md. Applicatitjn' May 10, 1948; Sl'iaIND.26,173

12-Claims.

This invention is a novelcarburetor for hi pressure valves usedinconnection withapparatus for feeding granular or finely divided solidmaterial from a feed hopper at atmospheric pressure into a mixingchamber having a: pressure above atmospheric, in acontinuous operation,the present invention being an improvement upon that disclosed in my U.S Letters Patent No. 2,.- 428,995, issued October 14, 1947; also upon myjoint application Serial No. 772,034,.filedseptember 4, 1947,-nowabandoned. While the. invention is susceptible to many applications, thesame is particularly adapted for feeding pulverized coal for thoroughmixture with a stream of high pressure air passingthroughsaidcarburetor.

The principal object of the present invention is to provide novel meansof mixing air: and a finely divided or pulverized coalzin'as nearlyper-- fectly constant proportions as possible; The pulverized coal isintroduced into carburetor by means of the feed throat valve arrangedtobring the coal into the carburetor in an almost perfectly even fiow, itbeing the function of the carburetor tomix this even-flow of coal intoan even flow of air in as: nearly perfectly constantproportions-aspossi-ble; To do this, the coal-must be first removed fromits po'int of entry; i. e, the perimeter of the: valve: seat,immediatelyand completely; and secondly, the coalm'ust be thoro'ughlymixed into the air immediately after its removal from the valveseat.

A further object of the invention is tdprovide a carburetor of the abovetype inwhich the air is initially brought tangentially into 'adistribution chamber disposedat the inner portion oi the carburetor toimpart to the air a rotary motion aroundthe feed throat whichdistributes theair evenly with respect to an annular series of. louvresseparating the distribution chamber and a mixing chamberdisposed at theouter portion of the carburetor. These louvresare pitched at an'acuteangle to the flow of the air and their combined area is such that withthe proper volume and pressure therotation of the: airisin'creasedagreatly and its velocity is stepped up to a point where itwill remove the solid material from the feed throat valve in a positivemanner. These .louvres are disposed insuch a manner that the whirlinghigh velocity air in the mixing chamber is directed onto and completelyaround the perimeter of the feed throat valve seat which accomplishesthe first of my objectives. The: second objective is attained by simplyallowing. the solid material and high velocity air to whirl aroundwithin the mixing chamber. From the distribution side of the louvres'0n'-and as far as desired to convey it pneumatically,v the velocity ofthe air is never allowed to fall below 5000 feet per minutethis velocityin the mixing chamber creating an intense turbulence which thoroughlymixes the solid materialwith the air.

Thus it can be seen that I accomplish the first of my objectives bysupplying. air at a great enough velocity to insure the removal (of thesolidmaterial) as fast as it is fed through the feed valve and withenough pressure to make the operation perfectly positive. The secondobjective is accomplished by the greatturbulenc'e createdby the highvelocitiesused.

I will explain the invention with reference to the accompanying drawing,which illustrates one practical embodiment thereof to enable othersfamiliar with the art to adopt'and use the same; and will summarize inthe claims the novel features of construction and novel combinations ofparts, for which protection is desired.

In said drawing:

Figure 1 is a longitudinal-section through the carburetor,. showing thefeed throat, valve, and adjacent partsof thehopper.

Fig; 2 is an end elevation taken on the line 2--2',.Fig. 1, showing. thelo-uvres for-med between the distribution chamber and mixing chamber toimpart whirling motion to the primary air as it enters the mixing.chamber.

Fig. 3 is a section, partly in elevation, on the line 3-'3, Fig. 2'.

The feed hopper i is provided with a bottom la and an opening lb inits'end communicating with the inlet of a cylindrical feed throat casing2 having an inner wall 2a adapted to be secured, by bolts 3 or the like,to the end of hopper i.

Extending axially through the feed throat 2 is a shaft 4 having areduced end journaled in the far end wall of an annular mixing chamber5, hereinafter described, said end wall having a bore 511 receiving thereduced end of the shaft 4' and having an antifriction bearing 6 housedin an enlarged bore 51) of the end wall. The'outer end of bore 512 iscovered by a cap or plate T (Fig. 1), and a suitable packing 8 isinterposed between shaft 4 and an intermediate bore 50 in the end wallwhich packing 8 is compressed by a ring 9 threaded into the tapped outerend of the intermediatebor'e 50; as shown.

Around the feed throat 2 is an annular chamher A for primary airdistribution, the chamber A being formed between the exterior of thefeed throat: 2 and the inner wall 211 of the feed throat casing-andanannular outer wall Zb'and an outer end wall 20, the primary air, underpressure, being introduced thereinto through a pipe i which enters thelower portion of chamber A at an angle to or substantially tangent tochamber A, thus causing the air within said chamber to have a rapidswirling motion around th feed throat 2.

In the end wall 2c of chamber A are a series of louvres 211 preferably,but not necessarily, formed integrally therewith, the louvres 2ddischarging into an annular mixing chamber B formed between the end wall2c of the feed throat casing and the annular mixing chamber casing 5, asshown, whereby the air discharged through the louvres at an acute angleto the rotary motion of air in chamber A, will likewise have a swirlingmotion, the air emerging from a tangentially arranged outlet M. in thetop of the mixing chamber B. As shown, the mixing chamber casing has aninwardly extending hub portion 56 for the bearing for shaft 3, said hubpotrion imparting an annular shape to the mixing chamber B, and the hubportion terminating adjacent the outer face of the end wall 2c of theair distribution chamber A.

The outer end of the bore of the feed throat 2 is internally beveled asat 2e (Fig. l) and a disclike valve it, of rubber or other yieldabiematerial, is keyed on shaft 4 and has a beveled outer ed e l2fcorresponding with the beveled portion 2c of the feed throat, as shownin Fig. 1, a roundedged collar i3 around shaft i being interposedbetween the inner end of the hub 56 of easing i": and the outer face ofvalve 12. The shaft 5 carries a conveyor night 42) whose periphery makesa close contact with the bore of feed throat 2, the flight terminatingadjacent the inner face of valve !2, but extending into the hopper.

The flight lb during rotation of shaft i draws the finely divided coalor other material from hopper l and passes it outwardly of the feedthroat 2, past the valve [2 and into the mixing chamber B. Theresiliency of the material of valve 42, whether it be rubber, plastic ormetal, will cause the beveled periphery 22 of the valve to normally seatagainst the beveled portion 2a of the feed throat, but as the pulverizedmaterial is forced out of the feed throat the resiliency of valve l2will cause same to accommodate itself to any fluctuations in the flow ofthe finely divided or granular solid material. Thus in any case whetherthe feed hopper is empty or material is flowing, the valve l2 forms aseal which will prevent the high pressure in the mixing chamber B fromescaping backwardly through the feed throat 2 into hopper i, from whencethe same could pass directly into the atmosphere.

A secondary function of valve i2 is to cause the finely divided coal orother material to flow more evenly to the mixing chamber B, said valvebeing fixedly mounted on the shaft 4 and rotating with the materialbeing fed by the Lia, thus reducing wear on the valve 52. In event thehow of material stops, the valve 12 will assume its normal sealing orclosed position against the valve seat 26 and prevent loss of pressurefrom the mixing chamber B back through the feed throat.

The above construction provides novel means of mixing air and a finelydivided solid material such as pulverized coal in as nearly perfectlyconstant proportions as possible. The solid material is introduced intothe carburetor mixing chamber B by means of the feed throat valve 52which valve will bring the solids into the carburetor mixing chamber Bin an almost perfectly even flow, it being the prime function of thecarburetor to mix this even flow of solid material into an even now ofair in as nearly perfectly constant proportions as possible. To do thisthe solid material must first be removed from its point of entry, i. e.,the periphery 2c of the valve seat, immediately and completely; andsecondly the coal must be thoroughly mixed into the air at once.

Air is brought tangentially into distribution chamber A by inlet 10 insuch manner that the air has imparted thereto a rotary or swirlingmotion around the feed throat 2 thereby distributing the air evenly tothe series of louvres 26. disposed between the distribution chamber Aand the mixing chamber B. These louvres are pitched at an acute angle tothe how of the air and their combined area is such that, with the propervolume and pressure, the rotation of the air is increased greatly andthe velocity is stepped up to a point where it will remove the solidmaterial from the feed throat valve in a positive manner. The louvres 2dare disposed in such a manner that the whirling high velocity air isdirected on and completely around the perimeter of the feed throat valveseat 22, which accomplishes the first of my objectives. The secondobjective is attained by simply allowing the solid material and highvelocity air to whirl around in the mixing chamber B. From thedistribution side of the louvres, as far as desired to convey themixture pneumatically, the velocity of the air is never allowed to fallbelow 5000 feet per minute, the velocity in the mixing chamber Bcreating an intense turbulence which thoroughly mixes the solid materialwith the air.

Thus it can be seen that I accomplish the first of my objectives bysupplying air at a great enough velocity to insure that the removal ofthe solid material is as fast as it is fed and with enough pressure tomake the operation perfectly positive. The second objective isaccomplished by the great turbulence created by the high vclocitieswhich I used. The flexible feed throat valve l2 eliminates any backpressure and causes the pulverized coal to enter the mixing chamber B ina perfectly even flow. The primary air is brought into the mixingchamber B through the louvres 201 which are disposed at a very acuteangle to the flow of the air imparting a rotary motion to the airentering the mixing chamber. The areas of the louvres 2d and throughoutthe mixing chamber B are such that in combination with the pressure ofthe primary air a velocity of more than 5000 feet per minute ismaintained at all times. The primary air is brought into the carburetorat 0, tangentially, which causes it to flow around the feed throat 2 andthrough the distribution chamber A in a swirling manner whichdistributes it evenly to the louvres 2d, the air rotating in the desireddirection. The primary air and coal mixture leave the carburetor throughpipe M which is disposed tangentially on the far side of the mixingchamber B.

I claim:

1. In combination with a hopper for finely divided solid material, acarburetor for mixing said material at atmospheric pressure with airabove atmospheric pressure, comprising a feed throat extending from thehopper; a shaft extending through said throat; a conveyor flight on theshaft terminating adjacent the discharge end of said throat, theperiphery thereof slidably en-. gaging the walls of said bore; a wallenveloping the feed throat and forming therewith an annue;

5 lar air distribution chamber closed at both ends; an annular casingcontiguous to the outer end of the distribution chamber beyond thethroat and forming an annular mixing chamber; a resilient valve withinthe mixing chamber and normally closing the outer end of the throat; theouter end of the distribution chamber having an annular series oflouvres therein inclined in the same direction and discharging into themixing chamber; a tangentially disposed inlet for air under pressureinto the distribution chamber; and a tangentially disposed outlet fromthe mixing chamber.

2. In combination as set forth in claim 1, said louvres being disposedat an acute angle to the swirling movement of the air in thedistribution chamber, and being of such combined area that the airvolume and pressure of the swirling air chamber will immediately removethe material as it is discharged past the said valve, the air andmaterial swirling within the mixing chamber before passing through thesaid outlet.

3. In a combination as set forth in claim 1, the combined area oflouvres being such that the minimum air velocity within the mixingchamber will be substantially 5000 feet per minute, thereby setting upan intense turbulence therein to thoroughly mix the solid material withthe air.

4. In combination with a hopper for finely divided solid material, acarburetor for mixing said material at atmospheric pressure with airabove atmospheric pressure, comprising a cylindrical feed throat havinga bore communicating with the hopper; a shaft extending through saidbore; a conveyor flight on the shaft terminating adjacent the dischargeend of said bore, the periphery of said flight slidably engaging thewalls of said bore; the outer end of said bore being internally beveledto form a valve seat; an annular wall around and spaced from the feedthroat and forming an annular air distribution chamber closed at bothends; an annular casing contiguous to the outer end of the distributionchamber beyond the throat and forming an annular mixing chamber; aresilient valve mounted on and rotating with the shaft within the mixingchamber and having a beveled periphery normally seating upon and closingthe valve seat; the outer end of the distribution chamber having anannular series of louvres therein inclined in the same direction anddischarging into the mixing chamber; a tangentially disposed inlet intothe distribution chamber for air under pressure; and a tangentiallydisposed outlet from the mixing chamber.

5. In a combination as set forth in claim 4, said louvres being disposedat an acute angle to the swirling movement of the air in thedistribution chamber, and being of such combined area that the airvolume and pressure of the swirlin air will immediately remove thematerial as it is discharged past the said valve, the air and materialswirling within the mixing chamber before passing through the saidoutlet.

6. In a combination as set forth in claim 4, the combined area oflouvres being such that the minimum air velocity within the mixingchamber will be substantially 5000 feet per minute, thereby setting upan intense turbulence therein to thoroughly mix the solid material withthe air.

7. In combination with a hopper for finely divided solid material, acarburetor for mixing said material at atmospheric pressure with airabove atmospheric pressure, comprising a cylindrical feed throat havinga bore communicating with the hopper; shaft extending through said bore;a conveyor flight on the shaft terminating adjacent the discharge end ofsaid bore, the periphery of said flight slidably engaging the walls ofsaid bore; the outer endof said bore being internally beveled to form avalve seat; an annular wall around and spaced from the feed throat andforming an annular air distribution chamber closed'at both ends; acasing having an internal hubportion forming an annular mixing chambercontiguous to the outer end of the distribution chamber and beyond thesaid valve seat; a bearing for the shaft in the said hub; a resilientvalve on said shaft within the mixing chamber and having a beveledperiphery normally seating upon and closing the valve seat; the outerend of the distribution chamber having an annular series of louvrestherein inclined in the same direction and discharging into the mixingchamber; a tangentially disposed inlet into the distribution chamber forair under pressure; and a tangentially disposed outlet from the mixingchamber.

8. In a combination as set forth in claim '7, said louvres beingdisposed at an acute angle to the swirling movement of the air in thedistribution chamber, and being of such combined area that the airvolume and pressure of the swirlin air will immediately remove thematerial as it is discharged past the said valve, the and and materialswirling within the mixing chamber before passing through the saidoutlet.

9. In a combination as set forth in claim '7, the combined area oflouvres being such that the minimum air velocity within the mixingchamber will be substantially 5000 feet per minute, thereby setting upan intense turbulence therein to thoroughly mix the solid material withthe air.

10. In combination with a hopper for finely divided solid material, a,carbuertor for mixing said material at atmospheric pressure with airabove atmospheric pressure, comprising a cylindrical feed throat havinga bore communicatingwith the hopper; a shaft extending through saidthroat; a conveyor flight on said shaft terminating adjacent thedischarge end of said throat, the periphery of said flight engaging thewalls of said bore; the outer end of said throat being internallybeveled to form a valve seat; an annular wall around and spaced from thefeed throat forming an annular air distribution chamber closed at bothends; a casing having an internal hub portion forming an annular mixingchamber contiguous to the outer end of the distribution chamber andbeyond the said valve seat; a bearing for the shaft in the said hub ofthe mixin chamber casing; a resilient valve mounted on and rotating withthe shaft within the mixing chamber and having a beveled peripherynormally seating upon and closing the valve seat; a round edged collaron the shaft interposed between the inner end of the hub and the outerface of the said valve; the outer end of the distribution chamber havingan annular series of louvres therein inclined in the same direction anddischarging into the mixing chamber; tangentially disposed inlet intothe distribution chamber for air under pressure; and a tangentiallydisposed outlet from the mixing chamber.

11. In a combination as set forth in claim 10, said louvres beingdisposed at an acute angle to the swirling movement of the air in thedis- 1 tribution chamber, and being of such combined to thoroughly mixthe solid material with the air.

JOHN BERRIEN ROGERS.

area that the air volume and pressure of the Y swirling air willimmediately remove the mate- REFERENCES CITED riEll as it s discharged pthe Said Valve, the The following references are of record in the airand material swirling within the mixing chamfile f this patent; berbefore passing through the said outlet. 5

12. In a combination as set forth in claim 10, UNITED STATES PATENTS thecombined area of louvres being such that the Number Name Date minimumair velocity within the mixing cham- 1,545,230 Bernert July 7, 1925 herwill be substantially 5000 feet per minute, 2,127,693 McCanless et a1.Aug. 23, 1938 thereby setting up an intense turbulence therein go2,355,774 Baker Aug. 15. 194A

